1. Field of the Invention
The present invention relates to a surgical retractor for permitting a wide variety of surgeries through an operating window. More particularly, the retractor permits surgery through a small outer incision, i.e., outer operating window, while providing a field of operation within the patient's body, i.e., inner operating window, which is larger than the outer operating window.
2. Background Discussion
In many types of surgery it is necessary to make an incision in a patient through the patient's skin and underlying tissues to permit operating on internal organs, etc. of that patient. Thus the incision creates an opening through the epidermis, dermis, subcutaneous tissue (including fat cells), fascia (covering muscle), and muscle. In some cases, e.g., coronary by-pass, the incision must also cut through hard body tissue, i.e., sternum. A retractor is often needed to keep the tissues at either side of the incision sufficiently apart to keep open an operating window through which the surgery is performed. For example, sternal retractors are necessary instruments for performing coronary bypass surgery. See for example, U.S. Pat. No. 4,852,552 to Chaux, incorporated herein by reference. Retractors generally keep the operating window open by pushing the two opposed sides of the incision away from each other. Some retractors for endoscopic surgery are also provided with a fiberoptic mechanism to light the operating area. A retractor with a fiberoptic mechanism is disclosed by U.S. Pat. No. 5,503,617 to Jako. U.S. Pat. No. 5,503,617 to Jako asserts that its retractor has lower and upper blades wherein the angle of the lower blade relative to its lower blade mount and the angle of the upper blade relative to its upper blade mount can be adjusted independently. However, this device is somewhat complex.
Although a wide variety of surgical retractors are known, it would be advantageous to provide a surgical retractor which is easier to use than those commercially available, highly reliable, disposable, and more economical. It would also be advantageous to provide a surgical retractor which economically permits an internal operating window area which is larger than its external operating window.